Build a High-Powered Ubuntu Linux Workstation (part 3)

Virtualize Everything-- If Your Hardware Can Handle it

October 15, 2009

By
Paul Ferrill

In the firsttwo parts of this series we focused a great
deal on the hardware. Rightly so since you need good hardware properly configured
for any solid workstation solution. Once you have all that figured out you must
make some decisions regarding what software to install. It really does seem
like a waste of good CPU cycles to just install a vanilla desktop Linux
distribution. This final installment will look at several potential choices for
the base operating system and in detail at what we finally settled on.

Before you start burning install DVDs it's probably a good
idea to come up with a list of things you want your operating system to do. In
our case the biggest single requirement was the ability to do virtualization,
or running multiple operating systems on the same hardware at the same time.
This doesn't really narrow things down very well. In fact, it opens up a number
of options to consider from both the open source world and free (as in VMware's
ESXi and Citrix's XenServer) for personal use.

Choices and Challenges

When you take a look at the choices available for
virtualization software, you'll find they can be broken down into several
categories. The first and simplest choice is to use a basic emulation tool like
QEMU or VMware Player. Both offer
versions that run on all the popular Linux distributions and support a
multitude of guest operating systems. VMware probably has the edge in terms of
ready-to-go virtual images (or appliances) you can just download off the
Internet and run.

Both of these options use a hosted virtualization approach,
meaning there is a software application running behind the scenes taking care of
the interface between the virtual machine and the actual hardware. This can
slow things down a bit especially in disk or network intensive operations.

The second group of options is characterized by the ability
to run directly on the underlying hardware. This approach uses what's called a
hypervisor to manage multiple virtual machines at the same time. It typically
requires hardware with special virtualization support found in the latest Intel
and AMD processors. Many off-the-shelf systems come with this option disabled
in the BIOS, so you'll have to enable it to get things to work.

Candidates for this group include VMware's ESXi, Citrix's
XenServer and others. The obvious advantage to this group is the ability to run
directly on the hardware. You would want to choose one of these options for
running multiple server instances on the same box. This works really well for
server consolidation, isolation and the whole backup / restore process. Each
virtual machine uses a single image file that can easily be backed up to an
external storage device relatively quickly.

There are a few downsides to this approach. We ran into some
trouble when trying to install both VMware's ESXi and Citrix's XenServer. The
issue can probably be traced to hardware compatibility. VMware has a pretty
extensive list of compatible systems including specific motherboards and other
hardware. You can search for your system on their Compatibility
Guide web site. Alas, our shiny new gaming motherboard didn't make the
list.